Mine self-advancing roof support and method of relocating a mine winning face equipped with self-advancing roof support

ABSTRACT

A self-advancing roof support for the face roof support in underground mining operations, having a plurality of supporting frames with self-advancing mechanisms acting perpendicular to the breast of the working, which mechanisms advance the supporting frames in the direction of the breast of the working. In order to facilitate the relocation of a winning face equipped with such a self-advancing roof support, these supporting frames have a plurality of self-advancing gears acting parallel to the breast of the working, to successively shift the supporting frames in the lateral direction parallel to the breast of the working, so as to produce a cut or road for the installation of a new winning face at a head side of the face equipment and to advance the self-advancing roof support sideways into the road together with the complete face equipment while maintaining the formation.

The invention relates to a mine self-advancing roof support system forthe face roof support in underground mining operations, having aplurality of supporting frames with a self-advancing gear actingperpendicular to the breast of the working, so as to advance the roofsupport frames in the direction of the breast of the working.

A modern winning face equipped with a self-advancing roof support, ahigh speed winning machine and a continuously working face conveyorpermits relatively high winning speeds even with great lengths of thewinning face, and minimizes the intervals to transfer the complete faceequipment to another working location. This applies even where onlyrelatively short undisturbed lengths of the mining field are availablein the direction of face advancement due to the geological conditions asfound, for example, in pit coal mining operations. In addition,geological faults that cannot be cut through with the face equipmentoften appear also within the length of the mining field scheduled in thewinning plan, necessitating the frequent relocation of the winning face.

The relocation of the winning face is extremely costly because of thedismantling, transportation and installation costs associated with eachrelocation. As an example, in Germany, approximately 500 million dollarsis spent annually for such relocations of the winning face in German pitcoal mining operations. These high costs adversely affect theprofitability of the use of expensive winning face equipment.

As disclosed in DE-OS No 30 31 113, it is known that the relocationcosts can be reduced if the self-advancing roof supports of the faceequipment are immediately relocated in the gallery driven with ashort-breast winning machine instead of with a preliminary support.However, even this method does not reduce the dismantling,transportation and reassembly costs because the self-advancing roofsupport frames have to be individually dismantled, partiallydisassembled for transportation to the new installation site and thenreassembled again and set up at the new site.

In DE-AS No. 25 38 084, a method is described for long-breast winning inroom-and-pillar mining systems, wherein a conveyor combined with awinning machine is advanced in its longitudinal direction into a gallerypreviously driven for installation of a new winning face. That method,however, can be used only in room-and-pillar systems withoutself-advancing roof support and with a relatively short conveyor length.A face conveyor with the construction length commonly found in longwallmining systems cannot be readily displaced in the longitudinal directionbecause no abutment is available that would suffice for its greatweight. Moreover, the conventional self-advancing roof support cannot beshifted sideways.

It is therefore an object of the present invention to provide animproved self-advancing roof support system which significantlyfacilitates the relocation of the winning face equipped with such a roofsupport system.

It is a further object of the invention to afford a method permittingthe relocation of the complate face equipment to a new working sitewhile maintaining the formation.

It is a further object of the invention to provide face equipmentcapable of automatically migrating to a new starting position, therebybypassing unforeseen obstacles, geological faults or the like.

These objects are accomplished by a self-advancing roof support systemfor the face roof support in underground mining operations, having aplurality of supporting frames with a self-advancing gear actingperpendicular to the breast of the working, to advance the supportingframes toward the breast of the working, and with additionalself-advancing gears acting parallel to the breast of the working. Theseadditional gears shift the supporting frames successively sidewaysparallel to the breast of the working.

The self-advancing roof support according to the invention has theadvantage that it is capable of advancing sideways in the longitudinaldirection of the winning face parallel to the breast of the working, andthus is capable of leaving the winning face by migrating sideways and ofadvancing sideways into a new cut or road for the installation of a newwinning face.

This sideways migration requires that space be provided for the lateraldisplacement of the supporting frame advancing at any given moment. Inorder to assure that such space is always available, a specialembodiment of the invention provides that the advancing gear actingparallel to the breast of the working be connected with asequence-controlling device to automatically displace sideways thesupport frames in successive order.

The improved self-advancing roof support of the invention permits theimplementation of a particularly simple method of relocating a winningface equipped with such a self-advancing roof support. In this method, acut or road for the installation of a new winning face or a connectionroad within the seam leading to the new working site is driven acrossthe width of the winning face at the head side of the face equipment,into which cut or connection road the support frames advanceautomatically by migrating sideways while maintaining their formation.

The method according to the invention permits relocating theself-advancing roof support in formation to a new working site withoutdismantling the roof support into its individual parts. This methodsubstantially reduces relocation costs so that the additionalinstallation costs of the second advancing gear for the equipment arecompensated for within a short time.

According to the invention, the face conveyor is automatically advancingin its longitudinal direction, migrating into the cut for theinstallation of a new winning face or into the connection road. In thisway, even the face conveyor need not be dismantled into its componentsand reassembled in the new cut. Face conveyors capable of automaticallyadvancing in the longitudinal direction and extending through curves,are the object of the older German patent application No. P 32 41 129,corresponding to U.S. patent application Ser. No. 547,945, filed Nov. 2,1983.

Furthermore, it is advantageous that the road for the installation of anew winning face or the connection road is cut with a short-breastwinning machine by a conventional method, wherein self-advancing roofsupports and the face conveyor continuously follow a short-breastwinning machine. In this way, the new starting position is practicallyprepared by the face equipment itself, which eliminates the requirementfor a separate cut or road.

The conventional longwall mining system is a rigid system with onlylimited adaptability. It is made much more flexible by the use of theinstant invention, which adapts this system to unforeseen geologicalfaults by the unproblematic relocation of the winning face.Consequently, more intensive exploitation of high-speed equipment isachieved.

Moreover, the short-breast winning machine, after the cut or road hasbeen completed, is advantageously used as a stable hole winning machine.

The objects of the invention are accomplished in a preferred embodiment,which uses a face conveyor and support frames which migrate sideways andadvance around curves at the end of the ending winning face, at theinlet of the cut, or, in the course of the connection road. Therefore,the complete face equipment advances in a closed formation even aroundcurves, permitting said equipment to assume any desired position withinthe mining field. As a result, it is particularly possible also toovercome larger distances by bypassing obstacles. This preferredembodiment also uses a conveyor capable of automatically advancing inits longitudinal direction around curves as has been disclosed in theaforementioned older German Application No. P 32 41 129, correspondingto U.S. patent application Ser. No. 547,945, filed Nov. 2, 1983.

It is advantageous to use the self-advancing roof support according tothe invention when setting up a new winning face. In mountain formationswith readily breakable roof layers, the lateral advancement of the faceroof support into a cut for the installaton of a new winning face maypose problems. Due to the alternating tightening or chucking andloosening of the support frames, the roof within the starting zone ofthe cut is subjected to high alternating loads, with the hazard that theroof may be subject to the so-called stamping effect, causing the hazardof destruction of the roof by break-ins. To avoid this hazard, the roofof the cut for the installation for a new winning face in conventionalsystems must be secured by additioal support measures, for example, byanchor supports.

To resolve this problem, the invention provides that a cut forinstalling a new winning face is extended beginning at the basic linestep by step in each case by the width of a support frame and is widenedby the width of a winning road extending in front of the support frame.In addition, the support frames are advanced after each extension andwidening of the cut sideways by one length of the step in each case, andby one length of the step in the direction of the breast of the working.Thereafter, the row of support frames is extended or lengthened from thebasic road step by step by newly installed support frames until allsupport frames have been brought into the winning face.

According to the invention, the row of supports migrate into the cutbeing lengthened step by step, and are advanced after each lateral stepin the direction of the working by the width of the winning road. Inthis way, the row of supports is always located beneath newly exposed,still undestroyed roof. The hazard of the stamping effect which coulddestroy the roof is avoided in a simple manner, so that no additionalsupport measures are required in the cut for installing a new winningface. With this method, the lateral advancement of the row of supportsthat is being extended step by step is combined with the first workingof the winning face. Consequently, coal may be mined and conveyed in aparticularly advantageous way even while the winning operation is stillbeing set up. Of course, when one reaches the end of the mining field,the same method can be employed in the reverse sequence by shorteningthe row of supports that is advancing in the direction of the winningface. In this way, the roof-damaging stamping effect can be avoided alsowhen the support frames are laterally removed from the winning face asthe mining operation is being terminated.

So that conventional winning and conveying equipment can be immediatelyused at the breast of the working in a new mining operation; the faceconveyor automatically advances in a conventional manner in itslongitudinal direction, migrating into the cut along the developingbreast of the working.

Most desirably, a short-breast winning machine is employed for extendingthe cut, and the long-breast winning machine of the face equipment isused for the widening of the cut or road for installing a new winningface. The short-breast winning machine, after the face equipment hasbeen installed, is then used as a stable hole winning machine.Therefore, it is thus possible to set up the winning face exclusivelywith the help of components normally included in the face equipment.

Other objects and features of the present invention will become apparentfrom the following detailed description when taken in connection withthe accompanying drawings which disclose an embodiment of the invention.It is to be understood that the drawings are designed for the purposesof illustration only, and are not intended as a definition of the limitsand scope of the invention. In the drawings wherein similar referencenumerals denote similar elements throughout the views:

FIG. 1 is a schematic top view of a self-advancing roof supportaccording to the invention migrating in the longitudinal direction ofthe winning face;

FIG. 2 is a schematic top view showing how the face equipment is guidedthrough a curve; and

FIG. 3 is a flow diagram for the set-up of a new winning face with aself-advancing roof support according to the invention.

Referring now in detail to the drawings, a plurality of individual faceroof support frames 10, is provided with advancing means, such as thehydraulic piston and cylinder 11, acting perpendicular to the breast ofthe working in the direction of the breast of the working. Each means 11permits each roof support frame 10 to advance in the direction of thebreast of the working. The advancing means 11 corresponding to roofsupport frames 10 are jointly secured on an anchoring beam 12 arrangedin front of the support frames 10. When each individual support frame 10of the group advances, this anchoring beam 12 is held back or retainedby the advancing means 11 of the remaining support frames 10. Anchoringbeam 12 serves as the abutment for the advancing action of the supportframes 10 advancing at that moment. The advancing means 11 are movablysecured on the support frames 10 on the one side and on the anchoringbeam 12 on the other side in a way such that the support frames 10 arecapable of displacement in the longitudinal direction of the winningface with swivelling of the advancing means 11. Alternatively, theadvancing means 11 may be secured on the anchoring beam 12 displaceablyand lockably hinged in the longitudinal direction of the winning face ina way such that they are capable of being displaced in the longitudinaldirection of the winning face. The anchoring beam 12 may be replaced bya face conveyor consisting of segments capable of being urged againsteach other. In order to permit a displacement of the face roof supportframes 10 in the longitudinal direction of said conveyor, the advancingmeans 11 may be similarly hinged on the conveyor. The advancing means 11may be deteched from the conveyor or connected to the conveyor in a waysuch that they are solidly fixed thereon under pulling and pushingconditions, but displaceable with the conveyor in the longitudinaldirection of the winning face.

Furthermore, the support frames 10 have the advancing means 13 acting inthe longitudinal direction of the winning face. Means 13 can be extendedsideways and supported by each of the other advancing means bysupporting plates 14 which, if necessary, comprise components of the gapsealing mechanism between each of the support frames 10. By extendingand retracting said advancing means 13, it is possible to successivelydisplace the support frames 10 sideways, in each case by the urging ofthe advancing means 13. Of course, within each group of support frames10, sufficient space has to be available sideways, to compensate for onefull step of displacement sideways, of each support frame 10. Becausethe space conditions permit a lateral displacement of the group ofsupport frames 10 only in successive order, the advancing means 13 are,therefore, controlled by an electronic sequence controlling system 15,which initiates the lateral advance of each support frame 10 only afterthe preceding adjacent support frame 10 has advanced a predetermineddistance. Such conventional sequence-controlling devices are basicallyknown in connection with self-advancing roof support systems andtherefore not shown in detail in the drawing.

The invention permits new ways of relocating a winning face because theself-advancing roof support frames can be readily displaced in thelongitudinal direction of the winning face. Such a method for relocatinga winning face is explained as follows:

FIG. 1 shows a top view of a winning face in a horizontal seam withtrailing working roads. The winning face is supported by the group ofself-advancing roof support frames 10 according to the invention. A faceconveyor 20 is disposed in front of the self-advancing roof support.Conveyor 20 is not connected with the self-advancing roof support, butis capable of automatically advancing in the longitudinal direction andof travelling through curves while advancing. Such a face conveyor isthe object of the older German application No. P 32 41 129.

A conventional winning machine, preferably a cutting winning machine,works ahead of the face conveyor 20. As shown in FIG. 1, in a typicalmining problem, one encounters a geological fault within zone "A" of thebreast of the working, which stands as an obstacle. This problem issolved by displacing the winning face in its longitudinal directionalong the path length "a". Therefore, the winning face evades the faultby turning sideways.

In a preferred embodiment, a barrier or dam "D" supporting the roof isconstructed first at the edge of the winning face facing the directionof displacement, using rapidly setting dam construction materials.Subsequently, a short breast winning machine 30 is installed at the faceside "b" of the winning face. This winning machine prepares a cut forthe installation of a new winning face across the width of the winningface, into which cut or road the support frames 10 advance,automatically migrating sideways while retaining their formation side byside. In the same way, the face conveyor 20 automatically advances inits longitudinal direction into the cut prepared by the short-breastwinning machine 30 until the entire face equipment has been displacedsideways by the distance "a" and the winning face can again start thelong-breast mining operation. Generally, the support frames 10 and theface conveyor 20 advance simultaneously with the progress in the workingof the short-breast winning machine 30, which, for the normal operation,can be swivelled by 90° and used as a stable hole winning machine. Forexample, the short-breast winning machine 30 may be a conventionalcutting machine, partial cutting machine or also a continuous miner.

The space vacated by the laterally advancing support frames 10 at theopposite end of the winning face is supported by a stationary supportsystem 40 such as individual pillars and caps and/or gallery roofanchors. The face conveyor 20 is extended segment by segment inaccordance with the movement of the short-breast winning machine.

FIG. 2 shows how the total equipment of the winning face can berelocated, in a new starting position, such as a position which ispivoted or displaced by 90° as compared to the earlier position. In thepresent case, the support frames 10 and the face conveyor 20 aredisplaced from a connection road through a curve of 90° and advancedinto a cut for the installation of a new winning face that is pivoted by90°. To permit the elements to pass through the curve, the anchoringbeam 12 must be of an articulated design with joints that can be lockedfor the normal operation. If necessary, the advancing means 11 may bedetached from the anchoring beam 12 while the latter is advancingthrough the curve, in which case the roof, because of the lesser supportdensity necessarily available within the zone of the curve, isadditionally secured, with supports such as gallery roof anchors or thelike.

FIG. 3 shows the basic gallery 51 of a newly developed winning face.Disposed sideways adjacent to the basic gallery 51, a cut 52 forinstalling a new winning face has been prepared in which the new winningface is to be set up. A short-breast winning machine 53 works in the cut52, extending cut 52 in its longitudinal direction extendingperpendicular to the basic gallery. The working direction of theshort-breast winning machine 53 is indicated by arrows. In addition, along-breast winning machine 54 works in the cut, clearing a winninggallery 56 along the breast of the working 55 of the winning face to beset up. The long-breast winning machine 54 is displaceably mounted on aface conveyor 57, which is capable of automatically advancing in itslongitudinal direction into the cut. The discharge end of the conveyor57 is disposed in the basic gallery 51.

In the cut for installing the new winning face, a plurality ofself-advancing roof support frames 58, 59, 60, 61, 62, 63 and 64arranged generally in a row is present to the rear of the face conveyor57. An additional self-advancing roof support frame 65 is kept ready inthe basic gallery 51 for installation in the winning face to be set up.

When the short-breast winning machine 53 at the face side of the cut andthe long-breast winning machine at the breast of the working 55 of thewinning operation to be set up have each worked coal by the width of onestep, the self-advancing roof supports 58-65 may again be advanced byone step sideways and by one step in the direction of the breast of theworking 55. In this operation, either the step sideways or the step inthe direction of the breast 55 may be performed first, or both steps maybe performed simultaneously. However, it is important that eachsupporting frame 58-65 advance into the new mining field in a diagonalway by combining said two motions of displacement in a way such that therow of self-advancing roof supports always comes to be disposed underfreshly exposed roof. Therefore, the hazards of the stamping effect areavoided, which otherwise may destroy the roof. The self-advancing faceconveyor 57 advances into the cut 52 as the length of said cut 52increases. From the basic gallery 51, the self-advancing roof supportframes required in the newly developed winning face are installed oneafter the other. Backfilling material may be admitted into the space tothe rear of the row of roof supports and the roof material may bebrought down. Once all self-advancing roof supports have been installedin the cut, the short-breast winning machine 53 may be rotated by 90° inthe direction of the breast of the working to subsequently serve as astable hole winning machine.

While only several embodiments and examples of the present inventionhave been described, it is obvious that many changes and modificationsmay be made thereunto, without departing from the spirit and scope ofthe invention.

What is claimed is:
 1. A method of relocating a winning face by means ofa self-advancing roof support system by installing a new winning face atthe head side of the roof support system and which includes a pluralityof self-advancing roof support frames having a defined configuration, aplurality of advancing means acting perpendicular to the breast of theworking for advancing said plurality of self-advancing roof supportframes in the direction of the breast of the working, each of which isassociated with one of said roof support frames, a plurality ofadditional advancing means each of which is associated with one of saidroof support frames, acting parallel to the breast of the working, whichmeans cooperate to successively advance the self-advancing roof supportframes sideways parallel to the breast of the working, comprising thesteps of:extending a cut for installing the new winning face in thelongitudinal direction of the winning face at the head side of the faceequipment and widening the cut by the width of a support frame; andadvancing the self-advancing roof support into said cut by migratingsaid supports sideways parallel to the breast of the working whilemaintaining their configuration.
 2. The method as recited in claim 1,wherein the system additionally includes a face conveyor and the methodadditionally includes the step of advancing the face conveyor in itslongitudinal direction into said cut for installing the new winningface.
 3. The method as recited in claim 1, wherein extending a cut inthe longitudinal direction of the winning face for installing a newwinning face is accomplished with a short-breast winning machine, andthe method further includes the steps of continuously following saidshort-breast winning machine with the self-advancing roof support framesand the face conveyor.
 4. The method as recited in claim 3, furthercomprising the step of using the short-breast winning machine, oncompletion of the cut for the installation of said new winning face, asa stable hole winning machine.
 5. The method as recited in claim 1,further comprising the step of guiding the laterally advancingself-advancing roof support frames through curves at the end of anexpiring winning face.
 6. A method for setting up a new winning face ina winning gallery from a basic gallery in underground mining operationswith a self-advancing roof support system which includes a plurality ofself-advancing roof support frames in a row, a plurality of advancingmeans acting perpendicular to the breast of the working for advancingsaid plurality of self-advancing roof support frames in the direction ofthe breast of the working, each of which is associated with one of saidroof support frames, a plurality of additional advancing means each ofwhich is associated with one of said roof support frames, actingparallel to the breast of the working, which means cooperate tosuccessively advance the self-advancing roof support frames sidewaysparallel to the breast of the working, comprising the steps of:extendinga cut in the longitudinal direction of the winning face step by step,starting at the basic gallery, by the width of a self-advancing roofsupport frame and widening the cut by the width of the winning galleryextending in front of the self-advancing roof support; advancing theself-advancing roof support frames sideways parallel to the breast ofthe working by one length of the step and by one length of the step inthe direction of the breast of the working, after each extension andwidening of the cut; and extending the row of self-advancing roofsupport frames step by step from the basic gallery by newly installedself-advancing roof support frames until all self-advancing roof supportframes are installed in the winning face.
 7. The method as recited inclaim 6, wherein the system additionally includes a face conveyor andthe method additionally includes the step of advancing the face conveyorin its longitudinal direction into the cut along the developing breastof the working.
 8. The method as recited in claim 6, wherein extendingthe cut is accomplished with a short-breast winning machine and wideningthe cut is accomplished with a long-breast winning machine of the faceequipment so as to allow for installation of a new winning face.
 9. Themethod as recited in claim 8, further comprising the step of using theshort-breast winning machine, after the installation of the faceequipment, as a stable hole winning machine.
 10. A method of relocatinga winning face by means of a self-advancing roof support system byinstalling a connection road leading with a seam to the new site of theworking and which includes a plurality of self-advancing roof supportframes having a defined configuration, a plurality of advancing meansacting perpendicular to the breast of the working for advancing saidplurality of self-advancing roof support frames in the direction of thebreast of the working, each of which is associated with one of said roofsupport frames, a plurality of additional advancing means each of whichis associated with one of said roof support frames, acting parallel tothe breast of the working, which means cooperate to successively advancethe self-advancing roof support frames sideways parallel to the breastof the working, comprising the steps of:extending a cut in thelongitudinal direction of the winning face for installing the connectionroad leading with a seam to the new site of the working and widening thecut by the width of a support frame; and advancing the self-advancingroof support frames into said connection road by migrating said roofsupport frames sideways parallel to the breast of the working whilemaintaining their configuration.
 11. The method as recited in claim 10,wherein the system additionally includes a face conveyor and the methodadditionally includes the step of advancing the face conveyor in itslongitudinal direction into the connection road within the seam.
 12. Themethod as recited in claim 10, wherein extending a cut in thelongitudinal direction of the winning face for installing a connectionroad within the seam is accomplished with a short-breast winningmachine, and the method further includes the step of continuouslyfollowing said short-breast winning machine with the self-advancing roofsupport frames, and the face conveyor.
 13. The method as recited inclaim 12, further comprising the step of using the short-breastedwinning machine, on completion of the cut for the connection road, as astable hole winning machine.
 14. The method as recited in claim 10,further comprising the step of guiding the laterally advancingself-advancing roof supports through curves in the course of aconnection road within the seam.
 15. The method as recited in claim 10,further comprising the step of guiding the laterally advancingself-advancing roof supports through curves at the inlet leading to thecut.